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From: David Mosberger-Tang <David.Mosberger@acm.org>
To: linux-ia64@vger.kernel.org
Subject: Re: Attribute spinlock contention ticks to caller.
Date: Sat, 17 Sep 2005 01:08:45 +0000	[thread overview]
Message-ID: <ed5aea43050916180874700c2@mail.gmail.com> (raw)
In-Reply-To: <20050914222644.GA5036@lnx-holt.americas.sgi.com>

On 9/16/05, Robin Holt <holt@sgi.com> wrote:

> Can you site one instance where it is more helpful to know that _ANY_
> lock in the system is hitting ia64_spinlock_contention as opposed to
> the function which has the spin_lock() code?  I can recall times when
> network traffic was contending on locks and causing my application to
> appear to have a contended lock.  With this change, at least we know
> the degradation is do to something external.

Not sure if I can help siting it, but I can cite one recent example: I
was looking at a profile of a test which wasn't supposed to have any
contention.  Yet, ia64_spinlock_contention unexpectedly showed up
fairly high in the profile.  Turns out it was due to some left-over
debug code.  Of course, I was using q-syscollect so it was easy to see
who was calling the spinlock contention routine a lot...

  --david

-- 
Mosberger Consulting LLC, voice/fax: 510-744-9372,
http://www.mosberger-consulting.com/
35706 Runckel Lane, Fremont, CA 94536

  parent reply	other threads:[~2005-09-17  1:08 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-09-14 22:26 Attribute spinlock contention ticks to caller Robin Holt
2005-09-15  0:10 ` Keith Owens
2005-09-15  6:34 ` Stephane Eranian
2005-09-15  8:19 ` Stephane Eranian
2005-09-15 17:14 ` Robin Holt
2005-09-15 17:23 ` Robin Holt
2005-09-15 17:37 ` Luck, Tony
2005-09-15 22:29 ` Robin Holt
2005-09-15 22:54 ` Zou Nan hai
2005-09-16  9:37 ` Stephane Eranian
2005-09-16 22:29 ` Robin Holt
2005-09-17  1:08 ` David Mosberger-Tang [this message]
2005-09-18 23:06 ` Robin Holt
2005-09-19  1:18 ` David Mosberger-Tang
2005-09-19  8:35 ` Stephane Eranian
2005-09-19 15:17 ` Robin Holt
2005-09-19 17:52 ` David Mosberger-Tang

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